JPH0531690B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a bushing assembly, and more particularly to a bushing assembly suitable for use in a pivot joint of a vehicle suspension.

(Prior Art) A bushing assembly used in a pivot connection of a vehicle suspension, for example, a control arm bushing used in a connection between a control arm and a vehicle body or axle side member, generally has the following characteristics: A cylindrical elastic member made of a rubber material is interposed between two concentrically arranged inner and outer cylindrical members, and due to the spring characteristics of the elastic member, the axial center of the It is designed to absorb vibrations in the right angle direction. However, in such a bushing assembly, due to the torsional spring action of the elastic member, increasing the rigidity in the direction perpendicular to the axis also increases the torsional rigidity around the axis.

Therefore, between the cylindrical member and the elastic member,
It has been proposed, for example, in US Pat. No. 3,331,642 and U.S. Pat. According to such a bushing assembly, since the sliding member reduces the frictional resistance between the cylindrical member and the elastic member,
Regardless of the degree of rigidity in the direction perpendicular to the axis, the cylindrical member and the elastic member can be relatively easily rotated relative to each other around the axis,
Therefore, the rigidity around the axis can be reduced while maintaining the rigidity in the direction perpendicular to the axis.

(Problems to be Solved by the Invention) However, in the bush assembly including such a sliding member, solids such as soil and sand are present in the sliding part between the sliding member and the cylindrical member. When particles, muddy water, etc. enter, the sliding surfaces of these components become scratched, or rust occurs on the sliding surfaces of cylindrical members, which are usually made of metal materials, causing damage to the cylindrical members and their elasticity. Relative rotation (sliding) between the parts is impaired,
As a result, there was a risk that the effect of reducing the torsion spring action by the sliding member could not be sufficiently exerted.

(Means for Solving the Problems) The present invention has been made to solve the above-mentioned problems, and the gist of the invention is to solve the problems described above. A bushing assembly comprising: a predetermined elastic member interposed therein; and a sliding member interposed between the elastic member and the inner cylindrical member to reduce the torsional spring action of the elastic member; Further interposing a rigid sleeve member between the sliding member and the sliding member,
The end portion of the rigid sleeve member includes an outer flange portion extending radially outward and a large diameter cylindrical portion extending axially from the outer peripheral edge of the outer flange portion to the other end side, while the inner cylinder A retainer member located at an end of the member includes a cylindrical portion located outside the large diameter cylindrical portion at a predetermined distance, and the outer peripheral surface of the large diameter cylindrical portion and the cylindrical portion A sealing rubber is provided on either side of the inner circumferential surface, and the sealing rubber is brought into contact with the other of the inner circumferential surfaces, thereby sealing between the large diameter cylindrical part and the cylindrical part. be.

(Operation/Effect) In such a bushing assembly, there is a gap between the large diameter cylindrical portion of the rigid sleeve member and the cylindrical portion of the retainer member located at the end of the inner cylindrical member.
It is interposed between the rigid sleeve member and the inner cylindrical member because it is sealed by a seal rubber, thereby effectively preventing dirt, sand, muddy water, etc. from entering between them. The relative rotation between the sliding member and the rigid sleeve member and/or the inner cylindrical member is not impaired, so that the sliding member can fully exhibit its original effect of reducing the torsional spring action. This is possible.

Moreover, the seal rubber provided between the outer circumferential surface of the large-diameter cylindrical portion of the rigid sleeve member and the inner circumferential surface of the cylindrical portion of the retainer member acts in the radial direction between the inner tube member and the outer tube member. Since it is not subjected to the load of Since there is no relative displacement in the radial direction, a constant sealing effect can always be obtained despite changes in the load applied in the radial direction.

In addition, the sliding member is interposed between a rigid sleeve member and an inner cylinder member that have relatively high rigidity, and is protected by the rigid sleeve member and the inner cylinder member, so that Deformation of sliding members (change in inner diameter) due to vibration loads, etc.
This effectively prevents cracking, cracking, etc., thereby ensuring a good rotational resistance reduction effect and extending its lifespan.

(Example) Next, in order to clarify the present invention more specifically, an example of the present invention will be described in detail based on the drawings.

First, FIG. 1 is a longitudinal sectional view showing an example of a bushing assembly according to the present invention.
Reference numeral 10 denotes a cylindrical metal outer cylinder member, and a cylindrical metal inner cylinder member 12 is concentrically arranged at a predetermined distance on the innermost side thereof. These outer cylinder members 1
0 and the inner cylinder member 12, a cylindrical rubber block 14 as an elastic member is interposed, and the rubber block 14 and the inner cylinder member 12
A relatively rigid metal sleeve 16 as a rigid sleeve member and a pair of oil-impregnated polyacetal resin cylindrical bodies 18 and 20 as sliding members are interposed between the two. By attaching retainer members 22 and 24 having substantially U-shaped cross sections to both ends of the inner cylinder member 12, the bush assembly is assembled, and the retainer members 22 and 24 and the sleeve 16 are connected to each other. Annular seal rubbers 26 and 28 are provided between the ends.

As clearly shown in FIGS. 2 and 3, the outer cylinder member 10 has a stepped cylindrical shape consisting of a small diameter portion 30 and a large diameter portion 32. An outer flange portion 34 extending radially outward is provided at the end on the diameter portion 32 side, while a tapered surface 3 is provided at the end on the small diameter portion 30 side.
6 is formed, and is press-fitted from the small diameter portion 30 side into a predetermined mounting hole of a control arm or the like of a suspension arm (not shown) and is fixed therein.

Further, as clearly shown in FIGS. 4 and 5, the sleeve 16 includes a cylindrical portion 38 having a smaller diameter and a longer axial length than the outer cylindrical member 10;
Outer flange portions 40, 42 extend radially outward from both ends of the cylindrical portion 38, and large diameter cylindrical portions 44, 46 extend axially from the outer periphery of the outer flange portions 40, 42 toward the other end. It is composed of. The outer diameter of one outer flange portion 40 is larger than that of the other outer flange portion 42, and in the assembled state, the outer cylinder member 10
The outer flange portion 42 is located on the outer flange portion 34 side, and the outer diameter of the other outer flange portion 42 is smaller than the inner diameter of the small diameter portion 30 of the outer cylinder member 10.

The outer cylinder member 10 and the sleeve 16 are arranged concentrically, and the rubber block 14 is interposed between them. Such a rubber block 14
For example, as shown in FIG. 6, the outer cylinder member 1
0 and the sleeve 16 concentrically and vulcanization molding a predetermined rubber material within the annular space formed between them. In this way, the rubber block 14
At the same time as forming the rubber block 14, the rubber block 14 is vulcanized and bonded to the inner peripheral surface of the outer cylinder member 10 and the outer peripheral surface of the sleeve 16, so that the outer cylinder member 10, the sleeve 16, and the rubber block 14 are integrated. . Thereafter, the outer cylindrical member 10 is subjected to a drawing process, the rubber block 14 is pre-compressed, and the outer cylindrical member 10, the rubber block 14 and the sleeve 16 are firmly fixed.

Here, in this embodiment, the rubber block 14
During the vulcanization molding, the seal rubbers 26 and 28 are also vulcanized and molded separately from the rubber block 14, and are fixed and formed on the outer peripheral surfaces of the large diameter cylindrical portions 44 and 46, respectively. In addition, the seal rubber 26,
28 are provided with circumferential grooves 48 and 28, respectively.
A plurality of seals 50 are formed to fully exhibit their sealing effect. Note that the seal rubbers 26 and 28 are, for example, the large diameter cylindrical portion 44,
By forming notches etc. in 46, it is possible to integrally mold them with the rubber block 14, or they can be formed separately in advance and fixed to the outer peripheral surfaces of the large diameter cylindrical parts 44, 46 with adhesive or the like. There is no harm in doing so.

On the other hand, as shown in FIGS. 7 to 10, the cylindrical bodies 18 and 20 each have a cylindrical shape with an outer diameter that is approximately the same as the inner diameter of the sleeve 16, and one end thereof is is provided with outer flange portions 52 and 54 extending radially outward, and four axial grooves 56 and 58 are formed on the inner peripheral surface at equal angular intervals in the circumferential direction. These cylindrical bodies 18 and 20 have outer flange portions 52 and 54, respectively.
It is press-fitted into the cylinder of the sleeve 16 from the ends 60, 62 on which it is not provided, and is fixed to the sleeve 16 with the outer flanges 52, 54 in contact with the ends of the sleeve 16. However, at this time, the ends 60, 6 of both cylindrical bodies 18, 20
A gap of a predetermined length is formed in the axial direction between the two. The cylindrical body 18 is press-fitted into the end of the sleeve 16 on the outer flange 40 side, and its axial length is smaller than that of the cylindrical body 20. The outer flange part 40 of the other outer flange part 4
Correspondingly, it is larger than the outer flange portion 54 of the cylindrical body 20.

The inner cylindrical member 12, which is also clearly shown in FIGS. 11 and 12, has an outer diameter that is the same as or slightly smaller than the inner diameter of the cylindrical bodies 18 and 20, and has an axial diameter. The length is the same as or slightly larger than the length of the cylindrical bodies 18 and 20 press-fitted into the sleeve 16 to the outer ends thereof. Therefore, the inner cylindrical member 12 is inserted into the cylindrical bodies 18 and 20 with its outer circumferential surface in contact with or very close to the inner circumferential surfaces of both the cylindrical bodies 18 and 20, and the inner cylindrical member 12 Relative rotation (sliding) between the member 12 and the cylindrical bodies 18 and 20
is allowed. Although not shown, a suitable inner shaft is inserted into the inner cylinder member 12, and the inner shaft is attached to the vehicle body through a support member such as a suitable bracket.

By the way, when the inner cylindrical member 12 is inserted into both cylindrical bodies 18 and 20 in this way, both ends 6 of them
An annular central space 64 surrounded by the inner cylinder member 12 and the sleeve 16 is formed between the inner cylinder member 12 and the sleeve 16. Lubricating oil such as grease may be sealed, or the cylindrical bodies 18, 20 and the inner cylindrical member 1 may be sealed together.
This is where the lubricating oil applied to the sliding surface with 2 accumulates. In short, such space 64 is
It functions as an oil reservoir for lubricating oil that lubricates the sliding surfaces between the cylindrical bodies 18 and 20 and the inner cylindrical member 12, so that the lubricating oil is distributed between the inner cylindrical member 12 and both cylindrical bodies 18 and 20. This spreads over the entire sliding parts of the parts, allowing them to rotate smoothly relative to each other, and reducing wear on the sliding parts. Further, grooves 5 formed on the inner circumferential surfaces of the cylindrical bodies 18 and 20
6 and 58 facilitate the movement of lubricating oil especially in the axial direction, and as a result, a good lubrication effect can be obtained even at both ends in the axial direction separated from the space 64. . The space 64 has a size that can function as a lubricating oil reservoir, and the length of the cylindrical bodies 18 and 20 in the axial direction is determined based on the size of the space 64. Each is set.

Retainer members 22 and 24 are attached to both ends of the inner cylinder member 12, and as clearly shown in FIGS. 13 to 16, these retainer members 22 and 24 are respectively Donut-shaped disk portions 66 and 68 and inner cylindrical portions 70 and 72 that extend perpendicularly from the inner peripheral edges of the disk portions 66 and 68 and have an outer diameter that is approximately the same as the inner diameter of the inner cylindrical member 12. and disc parts 66, 68
The outer cylindrical portions 74 and 76 extend from the outer peripheral edge in the same direction as the inner cylindrical portions 70 and 72, and have a substantially U-shaped cross section. In addition,
The outer diameters of the disk portions 66, 68 are larger than those of the outer flange portions 40, 42 of the sleeve 16, respectively, and the lengths of the outer cylindrical portions 74, 76 are greater than the inner peripheral surface thereof in the assembled state. are sized to face the outer circumferential surfaces of the large-diameter cylindrical portions 44 and 46 of the sleeve 16.

The retainer members 22 and 24 are fixed to the ends of the inner cylinder member 12 by press-fitting their inner cylinder parts 70 and 72 into both ends of the inner cylinder member 12, respectively. At this time, the large diameter cylindrical portions 44, 4
outer cylindrical portions 74, 7 opposed to the outer circumferential surface of 6;
Seal rubbers 26 and 28 are provided on the inner peripheral surface of 6, respectively.
The outer peripheral surface of the seal rubber 2 is brought into contact with the seal rubber 2.
6 and 28 are compressively deformed between them. This creates an effective seal between the outer cylindrical portions 74, 76 and the large diameter cylindrical portions 44, 46, and prevents dirt from entering between the sleeve 16 and the inner cylindrical member 12.
Infiltration of sand, muddy water, etc. is prevented. Note that the thickness of the seal rubbers 26 and 28 is set to a size that allows for compressive deformation between the outer cylindrical portions 74 and 76 and the large diameter cylindrical portions 44 and 46, respectively, as described above, and provides a reliable sealing effect. -ing

Further, the disk portion 66 of the retainer members 22, 24,
68 is because the length of the inner cylindrical member 12 is the same as or slightly larger than the length between the outer ends of the cylindrical bodies 18 and 20 press-fitted into the sleeve 16. Flange part 5
2 and 54, and are allowed to rotate relative to each other. Moreover, annular end spaces 78, 80 are formed on the radially outer sides of the outer flange parts 52, 54 of the cylindrical bodies 18, 20, and these end spaces 78,
Since the space 80 functions as a lubricating oil reservoir like the space 64, the space between the retainer members 22, 24 and the cylindrical bodies 18, 20 is well lubricated, and the lubricating oil is kept in the end spaces 78, 80. , the space between the outer cylindrical portions 74, 76 and the large diameter cylindrical portions 44, 46 is more effectively sealed. The space 64 is provided at a position slightly closer to the retainer member 22 side, so that the retainer member 22 and the outer flange portion 52 of the cylindrical body 18 have a larger sliding area than the retainer member 24 side. The space between the two is also well lubricated.

Note that, as described above, a predetermined mounting shaft (inner shaft) is inserted into the inner cylinder member 12 of the bushing assembly assembled in this way, and is used to attach the control arm of the intended suspension, such as the A-arm, It will be attached to the vehicle body side as the front bushing and lower bushing of the I-arm.

In the bushing assembly configured as described above, the seal rubbers 26 and 28 seal between the large diameter cylindrical parts 44 and 46 and the outer cylindrical parts 74 and 76, and the sleeve 16 and the inner cylindrical member 12 are sealed. Since the intrusion of soil, sand, muddy water, etc. between the two is effectively prevented, the relative rotation between them by the cylindrical bodies 18, 20 is impaired due to the intrusion of the soil, sand, muddy water, etc. There is no danger. In particular, the sealing rubbers 26 and 28 are attached to the large diameter cylindrical portion 4 of the sleeve 16.
4, 46, and the retainer member 2
Since the outer cylindrical parts 74 and 76 of the bushings 2 and 24 are brought into contact with and pressed against the inner circumferential surfaces of the outer cylindrical parts 74 and 76, a good sealing effect can be obtained even when the two rotate relative to each other. Even if the assembly is subjected to loads in the radial direction, the large diameter cylindrical portions 44, 4
6 and the outer cylindrical portions 74, 76 are not displaced relative to each other in the radial direction, a constant sealing effect is always obtained, and the seal rubbers 26, 2
8 can be minimized, thereby increasing its lifespan. Moreover,
The seal rubbers 26 and 28 each have a plurality of grooves 4.
8, 50 are provided, and outer cylindrical portions 74, 76
Since it is designed to be brought into contact with and pressed in surface contact with the material, a reliable sealing effect can be obtained.

Further, since the cylindrical bodies 18 and 20 are press-fitted into the sleeve 16, the sleeve 16 functions as a resistance body against deformation of the cylindrical bodies 18 and 20, thereby preventing the cylindrical bodies 18 and 20 from being exposed to the outside. It does not deform or crack due to vibration loads, etc., and always maintains a high roundness, ensuring a good effect of reducing torsion spring action, and increasing durability against heat, etc. This can effectively improve its lifespan.

Furthermore, in this embodiment, the cylindrical bodies 18, 2
0 between the ends 60 and 62 and the outer flange portion 52,
Spaces 64, 78, and 54 are respectively provided on the radially outer side of
80 is formed, and these spaces 64, 78, 80
functions as an oil reservoir for lubricating oil such as rubber grease that is gradually supplied to the sliding surface.
2, 24, the lubricating oil is sufficiently distributed over the entire sliding part, the wear thereof is effectively reduced, and the effect of reducing the torsion spring action by the cylindrical bodies 18, 20 is further improved. . Moreover,
In this embodiment, since grooves 56 and 58 are formed in the axial direction on the inner circumferential surfaces of the cylindrical bodies 18 and 20, a sufficient lubrication effect can be obtained even in the portions separated from the space 64. be.

In the above embodiment, the axial groove 56 is formed only on the inner circumferential surface of the cylindrical body 18.
As shown in the figure and FIG. 18, in addition to the groove 56, four locations on the axially outer surface of the outer flange portion 52 corresponding to the groove 56 are provided with the groove 56 and the end space, respectively. Concave groove 8 communicating with 78
2, the sliding portion between the outer flange portion 52 and the retainer member 22 will be lubricated even better. Note that this groove 82 does not necessarily correspond to the groove 5.
It is not necessary to form the end space 7 in correspondence with the end space 7.
A similar lubricating effect can be obtained even if only by communicating with 8. Furthermore, by forming a similar groove in the outer flange portion 54 of the other cylindrical body 20, it goes without saying that the sliding portion between the outer flange portion 54 and the retainer member 24 is well lubricated. .

Although one embodiment of the present invention has been described above in detail based on the drawings, the present invention can be implemented in other embodiments as well.

For example, in the embodiment, the seal rubber 26, 2
8 are provided on the outer circumferential surfaces of the large-diameter cylindrical portions 44 and 46, respectively, but there is no problem in providing them on the inner circumferential surfaces of the outer cylindrical portions 74 and 76, respectively.

Further, in the embodiment, the seal rubber 26, 28
A plurality of grooves 48 and 50 are formed on the outer circumferential surface of the tube to enhance the sealing effect, but even if the grooves 48 and 50 are not provided, a certain degree of sealing effect can be obtained.

Further, in the embodiment described above, the cylindrical bodies 18, 20 and the inner cylinder member 12 are made to rotate relative to each other, but the cylindrical bodies 18, 20 are fixed to the inner cylinder member 12, and the sleeve 16 and the cylindrical body 18 and 20 can be rotated relative to each other, or the cylindrical body 1
It is also possible to configure the sleeves 8 and 20 to be rotatable relative to both the sleeve 16 and the inner cylinder member 12 without being fixed to either.

Further, in the embodiment described above, the sliding member is composed of two cylindrical bodies 18 and 20, and a predetermined lubricating oil storage space 64 is formed between the ends 60 and 62. But not necessarily the space 64
It is not necessary to form a sliding member, and the sliding member can be formed of an integral cylindrical member. Furthermore, the end spaces 78 and 80 do not necessarily need to be formed in the same way.

Furthermore, in the embodiment, the cylindrical body 18,
20 is said to be made of oil-impregnated polyacetal resin, but it may be made of other oil-impregnated plastic materials,
It is also possible to use metal such as oil-impregnated bearing alloy.

Furthermore, in the embodiment described above, seal rubbers 26 and 28 are provided at both ends of the bushing assembly.
If the mounting position of the bushing assembly prevents muddy water from entering from one end, the seal rubber 26 or 28 may be provided only at the other end.

Furthermore, in the embodiment, the retainer member 22,
24 is adapted to be attached to the inner cylinder member 12 by its inner cylinder parts 70, 72,
Without providing such inner cylindrical parts 70 and 72, when the bushing assembly is attached to a predetermined mounting shaft, the retainer member is tightened and fixed to the inner cylindrical member 12 by threading a nut or the like. Alternatively, by press-fitting a collar having a flange into the inner cylinder member 12, the retainer member may be sandwiched and fixed between the flange and the inner cylinder member 12.

Although no other examples are given, it goes without saying that the present invention can be implemented with various changes, improvements, etc. based on the knowledge of those skilled in the art without departing from the spirit thereof.

[Brief explanation of drawings]

FIG. 1 is an axial (longitudinal) sectional view of a bushing assembly according to an embodiment of the present invention. 2 is an axial sectional view showing the outer cylinder member of the bushing assembly shown in FIG. 1, and FIG. 3 is a view from the right side in FIG. 2. 4 is an axial sectional view showing the rigid sleeve member of the bushing assembly of FIG. 1, and FIG. 5 is a view from the right in FIG. 4. FIG. 6 is an axial sectional view showing the bush assembly of FIG. 1 in which an elastic member is vulcanized between the outer cylinder member and the rigid sleeve member. FIG. 7 is an axial cross-sectional view showing one cylindrical body as a sliding member in the bushing assembly of FIG.
The figure is a view from the right side in FIG. 9th
This figure is an axial cross-sectional view showing the other cylindrical body of the bushing assembly in FIG. 1, and FIG. 10 is a view from the right side in FIG. 9. 11 is an axial sectional view showing the inner cylinder member of the bushing assembly of FIG. 1, and FIG. 12 is a view from the right side in FIG. 11. 13 is an axial cross-sectional view showing one retainer member of the bushing assembly of FIG. 1, and FIG. 14 is a view from the right side in FIG. 13. 15 is an axial sectional view showing the other retainer member of the bushing assembly of FIG.
The figure is a view from the left in FIG. 15. FIG. 17 is a diagram illustrating the main parts of another embodiment of the present invention, and is a front view showing one cylindrical body as a sliding member from the outer flange side, and FIG. 18 is a − It is an enlarged cross-sectional view. 10: Outer cylinder member, 12: Inner cylinder member, 14: Rubber block (elastic member), 16: Sleeve (rigid sleeve member), 18, 20: Cylindrical body (sliding member),
22, 24: Retainer member, 26, 28: Seal rubber, 40, 42: Outer flange portion, 44, 46:
Large diameter cylindrical part, 52, 54: Outer flange part, 64:
Space (center space), 74, 76: outer cylindrical part (cylindrical part), 78, 80: end space.

Claims (1)

[Claims] 1. A predetermined elastic member is interposed between an inner cylinder member and an outer cylinder member that are positioned concentrically, and a predetermined elastic member is interposed between the elastic member and the inner cylinder member. A bushing assembly including a sliding member for reducing torsional spring action, further interposing a rigid sleeve member between the elastic member and the sliding member, and an end portion of the rigid sleeve member, one consisting of an outer flange portion extending radially outward and a large diameter cylindrical portion extending axially from the outer peripheral edge of the outer flange portion to the other end side;
The retainer member located at the end of the inner cylindrical member includes a cylindrical portion located outside the large diameter cylindrical portion at a predetermined distance, and the retainer member is configured to include a cylindrical portion located at a predetermined distance apart from the outer circumferential surface of the large diameter cylindrical portion and the cylinder. A sealing rubber is provided on either one of the inner circumferential surfaces of the shaped portion and the sealing rubber is brought into contact with the other of the inner circumferential surfaces, so that a seal is established between the large diameter cylindrical portion and the cylindrical portion. A bushing assembly characterized by: 2. The sliding member is composed of two cylindrical bodies each having an outer flange extending radially outward at one end, and the outer flange of the two cylindrical bodies is located on the end side of the bushing assembly. When placed between the inner cylinder member and the rigid sleeve member, a predetermined central space is formed between the ends of the two cylinders where the outer flange portion is not provided. A bushing assembly according to claim 1. 3. Claim 1 or 2, wherein the elastic member is vulcanized and bonded to the inner circumferential surface of the outer cylinder member and the outer circumferential surface of the rigid sleeve member, respectively, to form an integral structure. Button assembly as described in section. 4. A bushing assembly according to any one of claims 1 to 3, wherein the sliding member is formed of an oil-impregnated plastic material. 5. Claim 2, wherein an end space sandwiched between the retainer member and the rigid sleeve member is formed between the seal rubber and the outer flange portion of the cylindrical body constituting the sliding member. Button assembly as described. 6. Claim 1, wherein the sealing mechanism between the large-diameter cylindrical portion of the rigid sleeve member and the cylindrical portion of the retainer member by the seal rubber is provided at each end in the axial direction of the bushing assembly.
The bushing assembly according to any one of items 1 to 5.